Insole

ABSTRACT

An insole for footwear comprises a main part made of expanded ethyl vinyl acetate. At the arch portion of the insole there is a thin mild steel member which can be deformed by hand into an appropriate shape to support the arch of the foot of the user. An intermediate member of the same material lies under the heel and arch portions of the main part and the steel member is sandwiched between the intermediate member and the main part. An opening is formed in the intermediate member below the heel portion. A plug fits into this opening.

This invention relates to insoles for use in footwear.

An insole comprises a heel portion to support the heel of the foot, an arch portion to lie below the arch of the foot and a front portion on the side of the arch portion remote from the heel portion. An insole normally comprises a soft resilient material which cushions the foot in use. The insole may also be an orthotic device which is normally shaped to provide support for the arch of the foot. Such an orthotic device is usually made to the specification of a podiatrist and as such is quite an expensive item.

According to one aspect of the invention there is provided an insole consisting of

-   a main part which in use is inserted into footwear and which     comprises a heel portion, an arch portion and a front portion; and -   a deformable member located at the arch portion which is capable of     relatively easy permanent deformation.

By the term “relatively easily permanent deformation” is meant that the item which can be deformed by hand but which when so deformed takes a generally permanent shape from which it would normally not be altered by the weight of the foot standing on the insole. A particular deformable member capable of relatively easy permanent deformation is a member comprising a thin strip of mild steel typically being a strip of mild steel of about one millimetre in thickness. The deformable member would normally be placed only at the arch portion of the insole.

The main part normally comprises flexible resilient sheet material such as expanded ethyl vinyl acetate. Conveniently on the underside of the main part at least the arch portion thereof is an additional support of flexible sheet material which preferably lies under the deformable part so that the deformable member may be sandwiched between the main part and the additional support. The additional support preferably also extends under the heel portion of the main part.

At the heel portion of the insole there is preferably an opening which is covered on the upper side of the main part by an upper member normally formed by part of the same material as the main part so that in use the spur of the heel would rest on the upper member above the opening so that there would be sufficient “give” to protect the spur of the heel from shock during walking.

Desirably a closure member is provided for the opening, the closure member comprising a bottom part and an upper part which fits within the opening. All the above parts are preferably bodies of revolution.

On the upper or preferably the lower side of the main part there are preferably markings to enable a user to cut the main part to the appropriate size to fit into footwear of various sizes.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings.

In the drawings:—

FIG. 1 is an underside view of an insole of the invention,

FIG. 2 is a plan of the insole,

FIG. 3 is an exploded perspective view of the underside of the insole, and

FIG. 4 is a detail exploded view of the insole with an additional support, and

FIG. 5 is a section on line 5-5 of FIG. 1,

Referring now to the drawings there is shown an insole 10 for a shoe. The insole 10 comprises a base part 12 that is of a shape that would fit into a very large shoe. The base part 12 is made of a resilient flexible sheet material conveniently expanded ethyl vinyl acetate of about three millimetres thickness.

The main part 12 comprises a forward portion 14, a heel portion 16 and an arch portion 18 which in use support the front of the foot, the heel and the arch respectively.

The underside 20 of the main part 12 is of a light colour. On the underside 20 of the forward portion there is printed a number of guidelines 22 which correspond respectively to the shape of the forward part of the sole of shoes of different sizes. Reference numerals are printed on the underside to indicate the size of the shoe that the insole 10 would fit if cut on the each particular guideline 22.

Running under the heel portion 16 and extending under the arch portion 18 and part of the forward portion is an intermediate member 24 which is made of a resilient flexible sheet material conveniently expanded ethyl vinyl acetate of about five millimetres thickness. The intermediate member 24 is bonded to the underside of the main part 12.

Sandwiched between the intermediate member 24 and the base part 12 is a deformable member 26 formed from mild steel sheet of one millimetre thickness. This deformable member 26 has a concave inner wall 28 and a convex outer wall 30. The walls 28 and 30 are joined by rounded end parts 32 to give the deformable member 26 a generally kidney shape. This deformable steel part 26 is bonded to the facing surfaces of the intermediate member 24 and the main part 12.

The heel portions 16 of the main part 12 and the rear of the intermediate member 24 have registering semi-circular rear portions 34. A circular opening 36 of a radius about three quarters of the radius of the rear portion 34 and being concentric with the rear portion 34 is formed in the intermediate member 24.

On the upper side of the heel portion 16 is a disc-shaped cover member 38 located coaxially with the opening 36. The cover member 38 comprises the same material as the base part 12. On the underside of the heel portion 16 is a plug 40 comprising a circular bottom member 42 on which is coaxially mounted a smaller diameter circular projection 44 that fits within the opening 36. The annular portion of the bottom member 42 outside the projection 44 rests under and supports the intermediate member 24. The cover member 38, the bottom member 42 and the projection 44 all are made from the same sheet material as the intermediate part.

In use, the forward portion 14 of the base part 12 is cut along an appropriate guide line 22 to fit a selected shoe. The user will now manipulate by hand the insole 10 so that the deformable steel member 26 is bent to an appropriate shape to provide support for the arch of the user. The plug 40 is fitted to the insole with the projection 44 fitting into the opening 36. The insole 10 is inserted into a shoe.

The user can now insert his/her foot into the shoe. The insole 10 will provide a resilient support for the foot. The steel part 26 will provide a generally permanent support for the arch of the foot. The spur of the heel of the user will be located above the opening 36 so that there will be substantial “give” when the heel of the shoe meets the ground to protect the heel of the user. However excess distortion of the of the cover member 38 is prevented by the plug 40.

It will be seen that the intermediate parts serve to raise the heel to accommodate the weight transfer on to the ball of the feet.

In a modification as illustrated in FIG. 5, an annular accessory 46 is provided. The accessory which is made of the same material as the plug 40 has an outer diameter the same as the bottom member 42 of the plug an a central opening 48 of the same diameter as the opening 36. The accessory 46 is applied to the underside of the insole 10 between the insole and the bottom member 42 of the plug 40 with the opening 48 registering with the opening 36 and with the projection 44 fitting into the opening 48. The accessory 46 provides additional resilience to the heel part of the insole and thus improved comfort for the heel of the user. In addition the annular accessory builds up the height of the insole 10 at the heel portion 16.

The accessory is preferably provided with bonding material on each of the annular surfaces covered with protective sheeting. This protective sheeting would be removed before tie application of the accessory to the plug and to the intermediate member so that the accessory 46 will bond thereto.

One or more identical additional annular accessories can be provided lying coaxially with accessory 46 to build up still further the height of the insole 10 at the heel portion 26. This will help compensate a user who has legs of slightly different length. Furthermore the height of the heel portion will accommodate the weight transfer on to the ball of the foot and indeed two insoles, one in each shoe, should be used for this purpose.

We have found that the steel member 26 can be deformed by hand into the appropriate shape to provide an arch support but will be of sufficient strength that it takes a generally permanent shape from which it would not normally be distorted back to the original position by the weight of the body of the user being applied to the part 24 through the arch of the foot of the user. In other words the steel member is capable of relatively easy deformation as herein defined. Thus the insole may act as an orthotic without the costs normally incurred in purchasing a pre-manufactured item. Subsequent changes can also be made by hand to the deformed portion of the steel part 26 if desired.

As is apparent a single size insole may be provided which is capable of use in most sizes of shoes by the user cutting along the appropriate guideline 22.

We have also found that ethyl vinyl acetate is particularly satisfactory because it is water repellant, odour free and washable.

In a modification (not, shown) the main part and the intermediate member with the deformable steel member located appropriately therein many be formed by injection moulding. Similarly the plug member 40 and the accessory/ies 46 may be formed by injection moulding. In this case the guidelines and reference numerals may be formed as indentations or low projections instead of being printed.

The invention is not limited to the precise constructional details hereinbefore described. For example, the insole may comprise other resilient material. The thickness of the base portion 12 may vary from about one millimetre to six millimetres. At the heel portion the height of the insole may extend to about eighteen millimetres. The size of the steel part may vary as desired and may indeed extend across the entire width of the arch part of the insole. Any other material which is capable relatively easy deformation may be used in substitution for the steel part.

The colour of the insole may vary provided that the guide lines and reference numerals are clearly visible. 

1. An insole consisting of a main part which in use is inserted into footwear and which comprises a heel portion, an arch portion and a front portion; and a deformable member made of a material that is capable of relatively easy permanent deformation.
 2. An insole as claimed in claim 1 wherein the said deformable member a thin strip of mild steel.
 3. An insole as claimed in claim 2 wherein the said strip of mild steel is of about one millimetre in thickness.
 4. An insole as claimed in claim 1 wherein the deformable member is placed only at the arch portion of the insole.
 5. An insole as claimed in claim 1 wherein the main part comprises flexible resilient sheet material.
 6. An insole as claimed in claim 5 wherein the main part comprises expanded ethyl vinyl acetate.
 7. An insole as claimed in claim 1 wherein on the underside of the main part at least the arch portion thereof is an additional support of flexible sheet material.
 8. An insole as claimed in claim 7 wherein the additional support lies under the deformable member so that the deformable member is sandwiched between the main part and the additional support.
 9. An insole as claimed in claim 7 wherein the additional support extends under the heel portion of the main part.
 10. An insole as claimed in claim 1 wherein there is an opening at the heel portion of the insole and wherein there is an upper part on the upper side of the main part which covers the said opening.
 11. An insole as claimed in claim 9 wherein the additional support is provided below the heel portion of the main part with is an opening and wherein an upper member is provided on the upper side of the main part to cover the opening.
 12. An insole as claimed in claim 11 further comprising a closure member is provided for the opening, the closure member comprising a bottom part and a smaller upper part which fits within the opening.
 13. An insole as claimed in claim 12 further comprising an accessory which fits between the said bottom part and the additional support and which has an aperture that registers with the said opening.
 14. An insole as claimed in claim 13 comprising a plurality of accessories which fit between the said bottom part and the additional support.
 15. An insole as claimed in claim 13 in which the accessory comprises an annular member having a central aperture which registers with the said opening.
 16. An insole as claimed in claim 1 wherein there are markings on the main part to enable a user to cut the main part to the appropriate size to fit into footwear of various sizes.
 17. An insole as claimed in claim 14 wherein the markings are provided on the underside of the main part.
 18. An insole as claimed in claim 10 further comprising a closure member is provided for the opening, the closure member comprising a bottom part and a smaller upper part which fits within the opening. 